Description

Defender was NGH's second America's Cup winner. The engineering and design of Defender reflects a consistent approach by NGH to create the lightest and strongest hull structure required for a design objective. In the case of most sailing vessels, the purpose is to concentrate weight (ballast) as low in the keel as possible to enable maximum sail area and power.

With Defender, NGH conducted more advanced research and experimentation than his first cup defender, Vigilant. NGH designed numerous custom components that had never been used on big yachts. The hull plating was Tobin bronze below the waterline and aluminum was used above and for deck plating and beams. He also designed a lighter steel mast. These innovations achieved the ballast and sail area ratio that NGH calculated, but presented unforeseen issues with corrosion caused by dissimilar metals and salt water.

Another important innovation was the cross-cut sail invention of NGH in 1894. The purpose of cross-cut sails was to provide more efficient sail shape to increase power. The method required specialty weaving of cotton by Lawrence Mills. Cross-cut sails have seams of cloth that run perpendicular to the leach (trailing edge of sails). In his Recollections, NGH wrote, "This was the beginning of the cross-cut sail era, and now they are made that way all over the world."